Present gyroscope-multi-axis accelerometer equipment bias performance of 2 deg/hr to 10 deg/hr and 0.2 milli "g" to 2 milli "g". Such equipment which uses piezoelectric bender beam transducers have inherently high electrical impedance and communicate from the rotor to the signal processor via sliprings. The sliprings limit the performance, useful instrument life and reliability, therefore reducing the product use to short time missions such as tactical missiles.
Prior art gyroscopes include spinning wheel gyroscopes, vibrating mass gyroscopes and Sagnac phase shift gyroscopes such as ring laser gyroscopes (RLGs) and fiber optic gyroscopes (FOGs). A hybrid gyroscope has been developed in which piezoelectric beams are caused to rotate about an axis. A rate input at other than the spin axis causes the beams to deflect, and the deflection is measured through electrical impedance. Changes in impedance are caused by the piezoelectric effect of the bending moments on the beam. Accelerometers, however, have been combined with gyroscopes in order to provide "multisensor" configurations in which various forms of rate are measured for navigation purposes. The accelerometer compliments the gyroscopic rate information and provides for the correlation of data which enhances the accuracy of both the accelerometer and the gyroscope. It has always been necessary, however, to include the unreliable slip ring contacts for electrical communication.
It is an object of the invention to provide a low cost, compact and accurate system for gyroscopically measuring rate and for measuring acceleration. Ideally, such rate information must be accurate enough to be used over extended ranges and extended time periods without constant updating.